Image projector, projected image pattern, laser driver, imaging device

Abstract

Image projection apparatus wherein, a focusing lens is controlled when a shutter is operated so that a contrast signal, obtained when a luminance signal from a camera signal processing circuit is supplied to an auto focusing detection circuit, may become maximum. A laser diode is driven to generate laser beams that are condensed into parallel laser beams by a condenser. These parallel laser beams are applied to a hologram plate and thereby diffracted. The diffracted laser beams interfere with each other, to produce a hologram image with sufficient contrast. Therefore, satisfactory focusing can be made in an auto focus mode of the contrast detection system or in a manual focus mode.

1. An image projection apparatus that is used with a camera apparatus and has a function to project onto an object a hologram reproduced image that is obtained by applying light of laser beams to a hologram plate, said image projection apparatus comprising:
 a laser light source for generating light of diffused laser beams;  
 a lens for converting said light of diffused laser beams to light of parallel laser beams; and  
 said hologram plate irradiated with said light of parallel laser beams, wherein  
 said lens is integrated with said hologram plate into one body unit.  
 
   
   
     2. A projection image pattern that is projected by an image projection apparatus that is used with a camera apparatus, possesses a function to project onto an object a hologram reproduced image that is obtained by applying light of laser beams to a hologram plate, and is comprised of a laser light source for generating said light of laser beams and said hologram plate, said projection image pattern being composed of at least part of first to fifth segments, that are comprised of one or a plurality of segments, each segment including a predetermined number of light spots arrayed in a straight line, wherein
 said first segment is provided in the center of a projected image at an angle of approximately 45 degrees with horizontal and vertical axes of an image pickup plane;  
 four said second segments are provided, at right angles with said first segment, at each vertex of a square that circumscribes a circle centered at the center of said first segment and has a predetermined length of diameter;  
 eight said third segments are provided, in parallel with said first segment, at each vertex and at each vertex and at a midpoint in each side of a square that circumscribes a circle centered at the center of said first segment and has a diameter twice the predetermined length;  
 twelve said fourth segments are provided, at right angles with said first segment, at each vertex and at points trisecting each side of a square that circumscribes a circle centered at the center of said first segment and has a diameter three times the predetermined length;  
 four said fifth segments are provided, in parallel with said first segment, at a midpoint of each side of a square that circumscribes a circle centered at the center of said first segment and has a diameter four times the predetermined length.  
 
   
   
     3. A projection image pattern according to  claim 2 , wherein the central light spot is removed from said predetermined number of light spots forming said first segment. 
   
   
     4. A camera apparatus comprising an image projection apparatus including:
 a laser light source for generating light of diffused laser beams;  
 a lens for converting said light of diffused laser beams to light of parallel laser beams; and  
 a hologram plate irradiated with said light of parallel laser beams and integrated with said lens into one body unit, wherein  
 said image projection apparatus projects onto an object a hologram reproduced image that is obtained by applying said light of parallel laser beams to said hologram plate, and  
 said camera apparatus performs an auto focusing operation by using a projected image of said hologram reproduced image projected onto said object.  
 
   
   
     5. A camera apparatus comprising an image projection apparatus including:
 a laser light source for generating light of diffused laser beams;  
 a lens for converting said light of diffused laser beams to light of parallel laser beams; and  
 a hologram plate irradiated with said light of parallel laser beams and integrated with said lens into one body unit, wherein  
 said image projection apparatus projects onto an object a hologram reproduced image that is obtained by applying said light of laser beams to said hologram plate; and  
 operation means for projecting said hologram reproduced image in a manual focus mode is provided.